OBJECTIVES: Acute diarrheal disease (ADD) remains a leading cause of morbidity and mortality in children under 5 worldwide. In Paraguay, the introduction of the rotavirus vaccine in 2010 aimed to reduce the burden of ADD in infants and young children. This study analyzed 31 years of public data on ADD morbidity and mortality in Paraguayan children under 5 and evaluated the impact of rotavirus vaccination. METHODS: Annual ADD incidence, total deaths, and mortality rates from 1993 to 2023 were obtained from public databases. Proportionate mortality due to ADD, cause-specific mortality rates, absolute risk reduction (ARR) and relative risk reduction (RRR), and joinpoint regression were calculated using EPIDAT 4.2 and Joinpoint 5.3.0 software, with data stratified by age group and vaccination period. RESULTS: Between 1993 and 2021, pediatric mortality in Paraguay declined steadily across all age groups. Following the introduction of Rotarix in 2010, infant mortality dropped from 2.36 to 0.19 deaths per 1,000 live births (ARR, 0.83; RRR, 81.4%). Joinpoint analysis showed a decline in under-5 mortality between 2009 and 2012 (annual percentage change=−35.2%, p<0.05), followed by stabilization. ADD incidence increased until 2019 and then declined, while vaccine coverage exceeded 70%. CONCLUSIONS Paraguay has sustained declines in infant and childhood mortality over 3 decades through improvements in healthcare and immunization, with the 2010 introduction of Rotarix reducing the mortality rate by 43 deaths per 100,000 infants under 12 months. These results underscore the impact of vaccination and health system strengthening, while highlighting the need to monitor emerging threats.